Nonsense. It was no different to what they all face. Or at least anyone who goes against the status quo. The left just has an insane chip on its shoulder. Obviously his past comments will be investigated, twisted, explored. His economic policies gone through with a firm tooth comb etc. The guy could have been prime minister. That is scrutiny. You just call it an orchestrated political assassination. What do you call it if it's Farage then?
We probably agree on how the media try to twist and sensationalize things but for you to think it only applied to Corbyn (whereas I acknowledge it applies to all) is you being dishonest, or perhaps you just don't know about the other examples?
One of the greatest being the programme channel 4 put out called "UKIP: The first 100 days" which is still the most extraordinary biased intervention I have ever seen from a public broadcaster into an election.
https://www.bbc.com/news/entertainment-arts-31505966